Every national park on this list is spectacular today and will still be worth visiting in a decade — but "worth visiting" and "unchanged" are different things, and for these ten parks specifically, the gap between the experience available now and the one likely available in ten or twenty years is wide enough to matter. Glaciers are retreating on measurable annual timelines, reefs are bleaching under recorded temperature thresholds, and visitor volumes are forcing infrastructure changes that will alter how these places can be experienced. None of this is speculative alarmism; it's drawn from the same monitoring data park services themselves publish. Here are ten parks where the case for visiting sooner rather than later rests on documented, ongoing change.
Glacier National Park, USA
Glacier National Park had an estimated 150 glaciers when it was established in 1910; that number has fallen to roughly 25 named glaciers large enough to still be classified as such, and U.S. Geological Survey monitoring projects that most of the park's remaining glaciers could disappear entirely within the coming decades if current warming trends continue. The park's name will eventually outlive its glaciers on current trajectories, which makes the alpine landscape along the Going-to-the-Sun Road and the hike to Grinnell Glacier a genuinely time-limited experience rather than a permanent fixture, in a way that isn't true of the park's forests, wildlife, or valleys.
Great Barrier Reef (via nearby parks), Australia
The Great Barrier Reef has experienced multiple mass coral bleaching events since 2016, driven by marine heatwaves that push water temperatures past the threshold coral can tolerate before expelling the algae that give it color and much of its nutrition. Repeated bleaching events don't allow full recovery between episodes, and scientific monitoring has documented significant coral cover loss across large sections of the reef system over the past decade. The reef remains one of the most biodiverse marine ecosystems on Earth and snorkeling or diving trips from Cairns or the Whitsundays still deliver spectacular experiences, but the specific coral formations visible today are measurably different from those of twenty years ago, and that trajectory shows no sign of reversing on any timeline shorter than decades of sustained global temperature stabilization.
Sundarbans National Park, India and Bangladesh
The Sundarbans mangrove forest, the largest of its kind in the world and home to a significant wild Bengal tiger population, faces a direct and measurable threat from sea level rise, since a mangrove ecosystem this low-lying has limited room to migrate inland before losing the specific tidal balance that sustains it. Scientific projections of the region's habitable mangrove area under continued sea level rise are stark enough that conservation researchers treat significant habitat loss within this century as a near-certainty rather than a worst-case scenario. Visiting now, while the ecosystem still supports its full range of wildlife including the elusive tiger population that gives the region its fame, offers a version of the Sundarbans that later visitors may only be able to experience at reduced scale.
Kilimanjaro National Park, Tanzania
Mount Kilimanjaro's summit glaciers, the ones famously described in Hemingway's fiction, have lost a substantial majority of their total ice mass over the past century according to long-term glaciological surveys, and current projections suggest the mountain's remaining ice fields could vanish entirely within the coming decades. The trek to Uhuru Peak remains one of the most achievable high-altitude summits in the world and will continue to be a spectacular climb regardless of ice cover, but the specific experience of summiting alongside visible glacial ice — a defining image of Kilimanjaro for over a century — is on a firmly time-limited trajectory.
Everglades National Park, USA
The Everglades faces a compounding set of pressures — sea level rise pushing saltwater intrusion further into freshwater habitat, decades of water diversion for South Florida's agriculture and development, and the ongoing spread of invasive Burmese pythons that have measurably reduced native mammal populations across large sections of the park. Restoration efforts are underway and represent one of the largest ecosystem restoration projects in U.S. history, but the specific balance of freshwater marsh, mangrove, and wildlife that defines the Everglades today is under active, documented pressure from multiple directions simultaneously, making the park's current ecological composition less stable than its protected status might suggest.
Jasper National Park, Canada
The Athabasca Glacier, the most visited glacier in North America and the main icefield attraction in Jasper National Park, has retreated significantly over the past century and continues retreating at a documented annual rate, with markers along the approach trail showing visitors exactly how far the ice has withdrawn just within recent decades. A 2024 wildfire also burned through significant sections of Jasper townsite and surrounding forest, a reminder that glacial retreat isn't the park's only fast-moving change — increasingly severe wildfire seasons across western Canada's national parks are altering forest landscapes on timelines far shorter than the natural fire cycles those ecosystems evolved with.
Huascarán National Park, Peru
Huascarán National Park protects the Cordillera Blanca, the world's highest tropical mountain range and home to the majority of Peru's glaciated peaks, and Peruvian glaciological studies have documented substantial glacial area loss across the range over recent decades — a particularly consequential trend given how many downstream communities depend on glacial meltwater for their water supply during the dry season. The trekking routes through the range, including the well-known circuits around Huascarán itself, still offer some of the most dramatic high-altitude scenery in South America, but the glaciers framing those views are retreating on a documented, ongoing basis.
Madagascar's Rainforest Parks
Madagascar's eastern rainforest corridor, including parks like Ranomafana and Andasibe-Mantadia that protect the island's iconic lemur species, has lost a substantial share of its original forest cover over recent decades to agricultural clearing and logging pressure, and the fragmentation of remaining forest into isolated patches poses a particular threat to lemur species that depend on continuous canopy to move between feeding and breeding areas. Madagascar's biodiversity is so distinctive — the vast majority of its plant and animal species exist nowhere else on Earth — that ongoing habitat loss carries outsized extinction risk, and several lemur species are already classified as critically endangered, making a visit to see them in intact habitat increasingly time-sensitive.
Joshua Tree National Park, USA
Joshua trees, the park's namesake species, face a documented long-term survival challenge from a warming and drying climate that studies suggest could eliminate the majority of the plant's current range within the park by the end of the century, since Joshua trees depend on a narrow band of temperature and moisture conditions and on a specific moth species for pollination that faces its own climate pressures. Young Joshua trees are already establishing at measurably lower rates in the park's warmer, lower-elevation areas than historical patterns would predict, a slow-motion range contraction that's difficult to see on any single visit but is well documented across repeated ecological surveys over time.
Torres del Paine National Park, Chile
Torres del Paine's glaciers, including the Grey Glacier that forms part of the park's iconic W and O circuit treks, have retreated measurably over recent decades as part of the broader, well-documented retreat affecting the Southern Patagonian Ice Field, one of the largest non-polar ice masses on Earth. The park has also faced several major wildfires over the past two decades, some caused by visitor negligence, that have burned significant areas of native forest that will take many decades to fully regenerate. The dramatic granite towers that give the park its name aren't going anywhere, but the glacial and forest landscape surrounding them is visibly different from what trekkers photographed even fifteen years ago.
Visiting Without Making It Worse
There's an obvious tension in writing about climate-threatened destinations that ends with an encouragement to go see them, since travel itself carries a carbon cost that contributes, in aggregate, to the exact pressures degrading these places. The more defensible framing isn't "go now before it's gone," which risks treating these parks as items to consume before expiration, but rather "go deliberately, stay longer, and let the visit actually change how you think about the broader problem." A single trip to a retreating glacier or a bleaching reef won't reverse anything, but understanding these changes as immediate and ongoing rather than abstract and distant is worth something, provided the visit is paired with the kind of attention — to a park's specific conservation challenges, to responsible operators, to a longer stay that justifies the travel footprint — that turns a bucket-list checkmark into something more genuinely useful.